Actuating mechanism for mechanical pencils



J. GARTENMANN 2,596,234

ACTUATING MECHANISM FOR MECHANICAL PENCILS I 2 SHEETS-SHEET 1 May 13, 1952 Filed Aug. 15, 1949 Inventor May 13, 1952 J. GARTENMANN ACTUATING MECHANISM FOR MECHANICAL PENCILS Filed Aug. 15, 1949 2 SHEETS-SHEET 2 lnve'nliu W UNITED STATES PATENT OFFICE ACTUATING MECHANISM FOR MECHANICAL PENCILS Joseph Ga-rtenmann, Zurich, Switzerland Application August 15, 1949, Serial No. 110,265 InSwitzerland J uly 2 6, 1 9 48 3 Claims. 1

This inventionrelates to an actuating mechanism on mechanical pencils of the type in which the writing leads are housed in cells formed by slots in the shaft of the pencil. The slots are kept in closed or open condition by means of a selecting mechanism. In the open condition of any one cell the lead may, due to its weight, and by proper positioning of the pencil, be brought from one cell into a feeder and firmly fixed therein in writing position or brought back from the feeder into its cell.

The actuating mechanism acts upon a selecting member which is rotatably disposed and is axially slidable, and is connected or coupled in known manner with the selecting mechanism andthe lead feeder. The operative movements of theselecting member depend on the working position of the feeder. The selecting member is locked against undesirable rotation and undesirable movements in axial direction.

The lead feeler commonly used resiliently opens when moved in axial direction by the actuator button and closes to its initial position when returned by spring pressure upon the selecting member, upon release of the actuator button. Thereby the feeder serves in the opening stroke to engage a lead coming from a simultaneously opened cell, or to release a lead gripped in writing position to cause it to fall back into its cell, which is open when the feeder is open.

The actuating mechanism of mechanical multilead pencils of the described type which acts on a selecting member locked against undesirable rotation andaxial movement is, according to this invention, characterized in this that the selecting member is arranged to include locking means and the inner cylindrical surface of the shaft contains guide-slots, which are provided with an axially extending free zone and an axially ex tending locking zone. The locking means are dis posed in relation to the guide-slots in such manner that they resiliently ride in circumferential directionover the guide-slots by rotationof the selecting member when said locking means are in cooperative position with the guide-slots in the free zone, the selecting member being locked against axial displacement while the locking means are located between two guideslots, and conversely when said locking means is positioned in the guide-slots the selecting member is capable of moving axially against spring-pressure, and further that when the lock ing means is positioned in the locking zone of said guide-slots the selecting member is locked against rotation and is free to move in axial di- 2 rection. The selecting member with the locking means in the free zone is rotatable clockwise or counter-clockwise. The locking means positively snap into the guide-slots indicating that it is in position for axial displacement, and the actuatorbutton per se does not participate in the locking effect to which the selecting member is subjected.

The actuator button may be detachably coupled with the selecting member so as to be freely rotatable when the pencil contains in its feeder a firmly gripped lead. This feature is useful in that no mechanical stress is exerted on any member of the pencil when the actuator button is being rotated inadvertently. The actuator button may be removable from the pencil, and may include means which are operative for a useful purpose.

When the design of the actuating mechanism provides for a button which is rigidly attached to the selecting member it may contain a removable portion which is operative for a useful purpose.

The various features and advantages of this invention will be apparent from the specification and the drawing, in which:

Fig. 1 is an elevational section of an actuating mechanism embodying the invention.

Fig. 2 is a cross-section along the line II-II of Fig. 1.

Fig. 3 is an actuator button of a different de sign, from that shown in Fig. 1.

Fig. 4 shows an actuator button with a removable portion which is formed toconstitutea pencil sharpener.

Fig. 5 is a, detail pertaining to the feature of a removable actuator button as seen on line V--V of Fig. 1 in the direction of the arrow.

Fig. 6 illustrates in an axial section the actuating mechanism together with the mechanism which is actuated to select and guide a lead.

In the particular embodiment of mechanism according to the invention illustrated herewith, I is the housing of the actuating mechanism and also the continuation of the body 2 cf the pencil. The portion of the body between the feeder and the hous ng I is formed with longitudinal slots in longitudinal direction on the inside cylindrical surface, which slots register with cells capable of being opened and closed by a selecting mechanism. The lead in each cell can be transferred between the cell and the feeder in either direction. 3 indicates the selecting member of the known selecting mechanism connected in one of various known manners to the latter and the feeder. i designates a portion of another part of the selectin mechanism. The

member 4 and the feeder are no part of this invention. The part 5 is a tubular spacer which fixedly retains a disc 6 in its position-shown in Fig. 1. iii designates the top part of the pencil housing and may be made integral with the latter, or as shown on the drawing, it may be a bushing with outer threads engagin inner threads of the housing i. Between shoulder We of bushing i9 and the top edge of the housing i is clamped fast a clip l9bas fragmentarily shown in section on the drawing. The selecting member 3 is under the influence of a coil pressure spring i3 and contains according to this invention locking means which cooperate with.

guide slots 1, on the inner cylindrical surface of bushing iii-which is a part of the housing. The locking means on the selectin member}; consist of a cross-bore 3a through the axis of the cylindrical member 3, which bore contains a spring 9, a pm Hi and two spheres 8. The spheres 8 are pressed against the axially extending slots 1 provided on the inner cylindrical surface of the tubular bushing iii. The diameter D in the portion or locking zone B (see Fig. 1) of the inner cylindrical surface of the housing, upon which the member 3 is slidingly fitted, is smaller than the diameter a (see Fig. 2) in the portion or free zone A. In the locking zone B the selecting member 3 is locked against rotation, in that the pin iii is of such length as to prevent the spheres 8 from passing in circumferential direction from one slot to another. However, in the zone A, due to the relatively greater inner diameter a of the housing or bushing iii, the spheres 8 are able to pass in circumferential direction from one slot into another, enabling thereby rotation of the selecting member 3. When the spheres-by rotation of the member 3-move over the distance 0, Fig. 2. between two slots '1 the member is locked against axial sliding movement, in that due to the length of the pin iii the spheres are not able to move in axial direction upon the cylindrical wall of smaller diameter b. When the spheres 8 fall from the elevated part 0 into the guide slots l to a fixed rest-position by a snap-movement from the free zone A the relative operative angular position of the member 3 is indicated to the person operating the pencil by a click easily heard or felt.

The described locking means of the actuating mechanism locks the selectin member against undesirable axial sliding movements and indicates when it is in position to move axially. In the latter position the selecting member is locked against relative rotations, by the same locking means described.

'The actuatin button in combination with the ber are provided with radial toothings Ma and 3b meshing with each other when there is no lead in writing position in the feeder permitting as well known, the selecting member to be rotated. in that the spring i3 biases the selecting member against the actuator button H bringing thereby the radial toothings into mesh with each other. In the condition when there is a lead in writing position in the feeder, the button cannot rotate the selecting member. The spring 23 presses the actuator button with its projections Zia, against the annular top portion l9c of the bushing l9 which is part of the housing. The uncoupled condition of the actuator button and the selectin member 3 is advantageous in that the selecting member cannot be forced to rotate in'its locked position, whereby damages to the mechanical pencil by improper manipulations is efiiciently prevented.

The described coupling permits the use of an actuator button which is removably attached on the housing.

In Fig. 1 the button H is removably fastened on the housing and is provided with a conical. hole 253 with a surface suitably made to sharpen a lead with the actuator button when removed from the pencil. The removability is accomplished by the collar 2! having integral or rigidly fastened projections 2 la. This collar is rotatably disposed on a cylindrical portion of the button. The design permits moving the two opposite projections 2la into registering position with slot openings 22 on the annular top portion of the housing. This annular portion normally serves to retain the actuating button under the pressure of the springs E3 or 23. Shoulders 22c are integrally or rigidly fastened inside the annulartop portion i9c so as to form depending lugs on each side of the slots 22. The projections 2ia and said slot openings can be brought in registering position with each other. To attain this, the sleeve 2| is rotated until the projections 2 la abut the shoulders 22a (see Fig. 5) on the annular top portion it. The actuator button is pushed down until the projections 21a clear the lugs 22a, and are able to move into the slot-opening 22, whereupon the pressure of the coil spring 23 separates the button from the pencil.

Fig. 3 shows a modified design of the actuator button shown in Fig- 1. The rotatable sleeve of the modified actuator button is shaped to constitute an annular lead sharpener as shown in Fig. 3. In the use of the actuator button as a pencil sharpener the lead in writing position on the pencil is introduced into the hole 25a of the spring plate 25 against the pressure of the coil spring 25?) and the button with the collar. rotated and simultaneously moved axially of the button towards the pencil, whereby the lead point is sharpened. The dust coming from the sharpening of the lead point falls through the channel 26.

Fig. 4 shows an actuator button with an outer part 23 which is permanently and rigidly attached to the selecting member 3, which may be provided with locking means such as shown in Figs. 1 and 2. Inside the button part 28, a part 21 is removably fastened; screw-threading is shown for this purpose; a resilient washer to of a material such as soft rubber prevents accidental loosening of the screw connection. In an obliquely disposed slot of the part 27 a plate-like lead sharpening plate 21a is disposed. A hole 29 provides for a passage from the bottom of the part 21 to the plate 27a, as shown. When the part 2'? is being removed from the cylindrical part 28 it may be used as a sharpener for the lead of the pencil in that the lead is introduced into the hole 23, and the part 2? rotated by hand.

In Fig. 6 the selecting member 3 is shown at.- tached to the feeder I l, i5. i5 is the lower part of the housing i which cooperates in well known manner with the feeder part M. A sleeve 4 is rotatably fitted around the selecting member,

z aseaasc through its cylindrical wall a longitudinalslit (not shown) of awidth-that equals the width of the cells for the leads. The selecting member 3 is provided with a slot I 2 of a width which is also tsubstantiallyequal to the'width'of a cellfor the leads. The slot I2 corresponds axially exactly with the central passage of the feeder M, which is rigidly attached to the lower end thereof. Cooperation of the disclosed actuating mechanism "together with the mechanism which is actuated to select and guide a lead is as follows:

When a lead is in writing position in the feeder (dash-dotted lines in Fig. 6), the selecting member 3 is locked against rotation because in this position of the feeder M the spheres 8 are engaged in zone B of the guide-slots 1 in which position the pin Ill prevents the spheres from clearing the guide-slots I. If it is desired to retire a lead in writing position into its cell the actuating button is pressed down while the pencil is held upside down whereby the feeder due to its resiliency opens and the lead is guided back to its cell by gravity, passing through the slit in the selecting sleeve 4 and the slot [2. During the sliding movement of the selecting member 3 the spheres 8 prevent rotation of the member 3.

When there is no lead in the feeder l 4 the latter assumes the position shown in full lines. The

spheres 8 are thereby placed to occupy the upper zone A of the guide-slots 1. In this position the spheres 8 ride resiliently over the guide-slots as set forth previously. When the spheres move between two guide-slots, the selecting member is locked against sliding movement. Each guideslot determines a different cell of the leads, and permits therefore selection of any of the different leads in a cell. If the selecting member 3 is set for a lead to be brought into writing position the button II is pressed down to thereby rotate the selecting sleeve 4 and the slit thereof to register with the cell of the desired lead and also with the slot l 2 in the selecting member itself. In the pressed-down position of the selecting member the feeder l4, due to its resilient leaves I 5. is opened. Hence a free passage from the cell of the lead to be put in writing position is established through which the lead in the upright position of the pencil passes by gravity. After the lead has been adjusted by hand to its proper writing :1

position in the feeder I 4, the button I I is released, whereby the selecting member 3 and the feeder I4 are returned to the position which is indicated in broken line in Fig. 1, in which the spheres 8 remain engaged in the zone B of the guide-slots 7.

What I claim is:

1. An actuating mechanism for mechanical pencils which are composed of an outer housing, an actuating button, a selecting member slidably and rotatably disposed within said housing, the housing formed with cells arranged longitudinal- 1y, lead feeding means comprised of a feeder resiliently disposed at the bottom of the housing, and auxiliary mechanism to admit and guide a lead from a cell into said feeder or to return a lead in writing position in said feeder back into the cell, wherein the selecting member is provided with locking means, and the inner cylindrical surface of the housing is formed at its upper end with longitudinal guide slots, and said locking i for engagement with said guide slots,- iwhile J said selecting member is moved in axial direction,:said

- guide slots extending overtwo different-inside diam'etersof said inner cylindrical surface and thereby subdivided axially into an upper: and lower zone, said upper zone having a greater inside diameter than saidlowerizone, saidlocking means comprising a cross-bore in said selecting member, spring. means, a pin andat :leastiione sphere in said'cross-bore, said sphere: protruding from said cross-bore beyond the outer surface of the selecting member, said spring meansadapted to press saidsphere towards 'said guide'slots' fsaid pin byits length adapted to limit displacement of the sphere towards the inside of said .crosss'bore to maintain said spheres engaged with said guide slots in said lower zone, while permitting said sphere to resiliently ride over said guide slots in their upper zone, shoulders of said guide slot walls between the upper and lower zone cooperating with said spheres to prevent axial movement of the selecting member during rotation thereof when said spheres are moved over the side walls of the guide slots, and spring means opposed to axial movement of the selecting member and at such movement after the actuating button has been released to return the selecting member to its initial position.

2. In a mechanical multi-lead pencil having a sleevelike outer housing, a plurality of longitudinally extending cells within said housing, each said cell being adapted to contain a lead, lead feeding means within said housing, said means being axially slidable to protrude from the lower end of said housing, and a selector mechanism operable to permit the lead contained in each cell to pass from one of said cells into said feeding means, and in return, said selecting mechanism including a selecting member, said member being axially slidable and rotatable within the housing and extending towards the upper end of said housing, an arrangement whereby said selecting member may be alternatively locked against rotation or rotated as desired, said arrangement comprising a plurality of guide slots, each formed as a longitudinal continuation within the upper portion of said housing of one of said cells, recessing of the radially inner portion of the walls defining said guide slots at the upper extremity thereof to provide said continuation into a zone of greater inside diameter and a zone of lesser inside diameter, locking means for said selecting member, said locking means comprising a crossbore in the portion of said selecting member contiguous to said slots, at least one sphere protruding from said crossbore, a spring in said crossbore, said spring serving to force said sphere radially outwardly toward said slots, and a pin in said crossbore, said pin being of such length as to limit displacement of the sphere into the said crossbore to engage said sphere with the portion of said guide slots in the zone of lesser inside diameter, while permitting saidl sphere to ride resiliently over said guide slots in said zone of greater inside diameter, springs means urging said selecting member upward to dispose said sphere in said zone of greater inside diameter, and an actuating button insertable through the upper end of said housing and removable therefrom, said button extending axially within the housing, that portion of said button so extending within said housing being provided with means to coact with said selecting member to effect rotation thereof when said sphere is positioned in the zone of greater inside diameter, whereby the application of pressure on said button in opposition to said spring means forces said sphere down a guide slot and out of the zone of greater inside diameter and brings a lead into the feeding means.

3. The arrangement as described in claim 2 wherein the actuating button includes a coaxial sleeve about that portion of the button which extends axially into the housing, said button being rotatable relative to said sleeve, radially outwardly extending projections on said sleeve, an annular flange on the top of said housing, said flange being provided with slot openings flanked by shoulders through which openings said projections may be passed by axial movement of said button when said projections are in registry with said openings, and spring means between said selecting member and the lower end of said button, whereby said button may be removed by the pressure of said spring means when the projections are placed in registry with said slotopenings.

JOSEPH GAR'I'E'NMANN,

REFERENCES CITED FOREIGN PATENTS Number Country Date Switzerland Nov. 16, 1946 

